Family Brunoniaceae
Brunoniaceae Dum.~ Goodeniaceae Habit and leaf form. Herbs. Perennial; with a basal aggregation of leaves. Leaves alternate; spiral; more or less petiolate; non-sheathing; simple. Lamina entire; oblanceolate; pinnately veined; cross-venulate. Leaves exstipulate; without a persistent basal meristem. Leaf anatomy. Stomata paracytic. Stem anatomy. Secondary thickening developing from a conventional cambial ring. Reproductive type, pollination. Plants hermaphrodite. Pollination mechanism conspicuously specialized (via a cupular modification of the style and active pollen presentation, but different in detail from types in Goodeniaceae sensu stricto). Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in heads and in spikes. The ultimate inflorescence unit cymose. Inflorescences scapiflorous; terminal; densely spicate or capitate; with involucral bracts; pseudanthial. Flowers regular; cyclic; tetracyclic. Free hypanthium absent. Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; gamosepalous (with basal tube and subulate lobes). Calyx lobes markedly longer than the tube. Calyx regular; persistent. Corolla 5; 1 whorled; gamopetalous (at the base, the petals spreading). Corolla tube not noticeably adaxially split. Corolla lobes markedly longer than the tube. Corolla valvate; regular; blue. Androecium 5. Androecial members adnate (near the base of the corolla); all equal; coherent (above); 1 whorled. Androecium exclusively of fertile stamens. Stamens 5; inserted near the base of the corolla tube; isomerous with the perianth. Anthers cohering (connate around the style); dehiscing via longitudinal slits; introrse. Pollen grains aperturate; 3 aperturate; colporate; 2-celled. Gynoecium 2 carpelled. The pistil 1 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 1 locular. Styles 1; bearing an ‘indusium’ beneath the stigma. Stigmas 1; surrounded by a collar or indusium. Placentation basal. Ovules in the single cavity 1; ascending; anatropous; unitegmic; tenuinucellate. Endothelium differentiated. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids with elongated tips. Endosperm haustoria present; micropylar. Fruit non-fleshy; indehiscent; achene-like (enclosed by the persistent calyx). Seeds non-endospermic. Cotyledons 2 (thickened). Embryo straight. Seedling. Germination phanerocotylar. Physiology, biochemistry. Not cyanogenic. Iridoids not detected. Proanthocyanidins absent. Geography, cytology. Australian. Temperate, sub-tropical, and tropical. Australia. X = 9. Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Gentianiflorae; Goodeniales. Cronquist’s Subclass Asteridae; Campanulales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; campanulid; Order Asterales (as a synonym of Goodeniaceae). Species 1. Genera 1; only genus, Brunonia. Economic uses, etc. A commonly cultivated ornamental. Illustrations. |